Even with the awareness of the public regarding the need for powerful engines, which may be run efficiently, thereby using scarce fuel more effectively, substantial progress has yet to be made. Power and efficiency are substantially contradictory terms. A powerful engine does not have fuel efficiency. A fuel efficient engine usually lacks power.
A large number of parts go into a typical vehicle engine. While these parts are necessary to complete the engine, such parts add to the complexity of the engine. Yet the parts are necessary to achieve the desired results. If the number is reduced while maintaining the desired power ratio, great advantages can be achieved.
One attempt to maintain a set of desired engine qualities while simplifying the engine structure, is commonly known as a rotary engine. While the rotary engine provides a good power to weight ratio and shows great initial promise, it lacks the required durability.
Commonly, most vehicle engines run on fossil fuel. Combustion of the fossil fuel adds greatly to the pollution of the air and the ground. Other adverse effects of such combustion are also well documented.
For example, smog around large cities is mainly attributed to the internal combustion engine. Such smog has an extremely adverse effect on the health of people in and around the city. If this pollution can be reduced, so can the adverse effects of smog. If minimal change is required in order to accomplish pollution reduction, such an action renders the solution much more acceptable.
In order to reduce the use of fossil fuel, hybrid engines are coming into play. These engines switch back and forth between electrical power and fossil fuel power. Such a structure adds to the complexity of the vehicle and increases the chances for a malfunction. Thus, hybrid engines do not answer the required questions.
One of the problems with replacement engines, is that the gasoline in particular has a substantial amount of energy. For example, one gallon of gasoline with a weight of about three kilograms stores as much energy as 325 kilograms of batteries. Thus, electrically powered vehicles are complicated matters. These complicated vehicles are provided in order to reduce outside emissions and improve mileage. However, such advantages are not efficiently accomplished.
Also, with an engine, power is usually directly proportional to size. If an engine has a large cylindrical displacement and size, it generally has a capability of producing substantial power. If an engine has a small cylindrical displacement and size, it generally has a capability of producing less power. It is very desirable to produce power with a smaller engine.
Combining a smaller engine with sufficient power can lead to fuel efficiency. However, this combination is not technically feasible. The more powerful engines have a greater number of parts, and poor efficiency. It is extremely difficult to achieve both efficiency and power in an engine.
Attempts to make engines more efficient are not completely successful. Some of the attempts include adding various electronic or computer controls to an existing engine. Such additions do not give the major increases in efficiency and reduce fuel consumption as much as is desirable.